Internet has provided a long awaiting tool for connection and communication of people around the world. One of the most important applications and implication of Internet is its use in enhancing ideas and rapid information exchange between people or groups of people with similar interests. Such growing interest has created many applications and systems for group discussions and question answering, such as Yahoo ask, wikipedia, search engines, photo and video sharing, numerous portals, discussion groups, and the like. These systems and applications have accelerated knowledge discovery, creation of artistic contents, producing novel and useful inventions, and in general advancement of our understanding of the universe around us.